Athens, Ga. – Every winter, weather forecasters talk about the snow cover in the northern U.S. and into Canada as a factor in how deep the deep-freeze will be in the states. A new study by researchers at the University of Georgia indicates they may be looking, at least partially, in the wrong place.

It turns out that snow piling up over a band of frozen tundra from Siberia to far-northern Europe may have as much effect on the climate of the U.S. as the much-better-known El Niño and La Niña.

The new work, just published in the International Journal of Climatology, reports that to understand how cold (or warm) the winter season will be in the U.S., researchers and weather forecasters should also take a closer look at snowpack in northern Eurasia laid down the previous October and November.

“To date, there had been no thorough examination of how snow cover from various regions of Eurasia influences North American winter temperatures,” said climatologist Thomas Mote of UGA’s department of geography and leader of the research. “The goal of this research was to determine whether there is a significant relationship between autumn snow extent in specific regions of Eurasia and temperatures across North America during the subsequent winter.”

Co-author of the paper was Emily Kutney, a former graduate student in Mote’s lab who has since earned her master’s degree and left UGA.

While other scientists have postulated that snow cover on the Eurasian landmass has a strong effect on winters in North America, the new study is the first to narrow down the location of the area that causes the most direct effect on U.S. winters—an area in northwest Eurasia that includes part of Siberia—though the entire effective area extends as far west as northern Scandinavia.

“One difficulty in comparing previous studies is that they have used multiple definitions of Eurasian snow cover,” said Mote. “Our work looked at the role of various key areas of Eurasian snow cover on atmospheric circulation, including the systems called the Arctic Oscillation and the Pacific/North American teleconnection.”

The findings have new significance for seasonal climate outlooks, which predict whether upcoming seasons will be colder or warmer, or wetter or drier than normal. Years with extensive autumn snow in northwest Eurasia were associated with subsequent winter temperatures as much as seven degrees (Fahrenheit) lower near the center of North America. This difference is roughly the same as a one-month shift in climate.

Such information can be crucial for everything from agricultural to daily life in areas that normally have brutal winters. The crucial time to look at the snow cover in Eurasia is during October and November in order to understand the upcoming winters in North America, said Mote.

Even more complexity enters the system of interrelated climate phenomena when looking at the possibility that sea ice in the Atlantic and Arctic Oceans might affect Eurasian snow cover and thus winters in North America.

“It’s interesting, because it implies to us that the potential impact of this new idea could be as large or larger than El Niño and La Niña events,” said Mote.

The new study is more about seasonal climate predictions than short-term modeling for weather.

Mote also led a team that reported in 2008 a dramatic rise in the rate of melt in the ice sheet of Greenland. He and colleagues found that it was 60 percent higher in 2007 than ever before recorded. Mote used a nearly 40-year record of satellite data to discover the dramatic melting.

32 thoughts on “Northern Eurasian snowpack could be an important predictor of winter weather in U. S”

Ever get the feeling that the more they discover, the less they know? The uncovering of all of these feedbacks says one thing to my ears…that climate, as regards predictability, is largely chaotic. Weather, as it relates to causes in the “time neighborhood” is predictable.
Of COURSE Eurasian now pack affects North America. Exactly how, on the other hand, will likely remain a mystery. And then the Climatodruids want to isolate CO2 as a singular cause?? How do they do that in the face of all this other stuff that muddies the picture?

They never go to the source of the problem, like, why would there be more snow cover over eurasia? It is possible that the reasons for the extra snow cover are the indicators for the coming winter rather than the snow whic may only be a secondary effect.

It all points to cooling winters but we will see which prediction comes true and adapt as we always have. I have planned for a cooler winter and bought a Jeep Grand Cherokee. Fed up with the Discovery ending up in the garage every few weeks.

A chicken and egg study. Which comes first? The weather pattern variation that sets up the AO? Or the snow cover? I am thinking it is the weather pattern variation that then sets up the AO. The snow cover is a driver symptom, not a cause, of an impending US cold snap.

Presumably the amount of snowfall in the area concerned would also be related to the jetstream tracks and the polar high pressure cell characteristics.

So, both such snowfall and temperatures across the entire northern hemisphere would be a consequence of the surface air pressure distribution rather than that snowfall directly affecting North American temperatures.

“Our work looked at the role of various key areas of Eurasian snow cover on atmospheric circulation”.

They seem to be assuming that the snow cover drives the atmospheric circulation rather than changes in the atmospheric circulation driving snow cover.

To my mind one must first change the air circulation to get the snow cover. After all snow cover is not going to develop if the wind direction is predominantly from a more equatorial direction. The wind must switch first to come from a more polar direction and then the snow cover develops.

Stronger El Ninos clearly affect the air circulation from below and there is an increasing groundswell of opinion that the sun somehow affects the air circulation from above. The recent deep solar minimum at the same time as a record negative AO does not seem likely to be mere coincidence.

In comparison any effect from more GHGs is insignificant and probably unmeasurable.

Also, some trees don’t have leaves when there is snow on the ground. These trees lets you see the snow from the sky. So the ratio of conifers to trees-with-leaves can change the albedo of the region from autumn to spring. Climate is a complex topic.

Did they just cast about looking for links like an Easter egg hunt, or did the idea suggest itself from other sources. This is weird science. Did they reject a whole bunch of things they investigated before finding the snow pack in siberial connection, such as changes in penguin fertility with climate.

Henry chance says @ June 25, 2011 at 7:12 am ” Many like Hansen claim climate is tied to only one variable and that is CO2 and the Co2 is connected to only one cause and that is human benefitting from combustion.:

Unless you can prove that CO2 is the only variable that is used in modern climate science research and modeling that is a strawman argument Henry, and inherently a logical fallacy.

If this line of thinking is pursued long enough, every chicken that lays a weather egg is in turn hatched from another chicken laying an egg. Nothing says that every weather region has to have come from one upstream source, either.

To those who are arguing about whether the link is causual or not , it should be noted that from my brief look at it they are only claiming that the Eurasian snowpack could be a predictor of cold US winters, not the cause of them.

I would sternly caution them to take note of the switch flips ~1970 & ~late 1980s, which make it absolutely clear that complex numbers are needed to elucidate the nature of interannual spatiotemporal chaos (which should absolutely NOT be confused with temporal chaos, which differs fundamentally — given the widespread misconceptions of temporal climate chaos, this fundamental difference cannot be sufficiently emphasized).

For too long, there has been widespread misinterpretation of ENSO’s effect. It’s a dead simple exercise to show North American interannual patterns tracking NPI more closely than SOI — for example: a west coast station at about 49 degrees North:

It might be very helpful if we had a greater variety of solar experts volunteering comments. Corbyn, for example, was able to (1) see exactly what key piece of information I was missing and (2) address it thoroughly in 1 succinct (& polite) e-mail. Svalgaard, in contrast, provided tons upon tons upon tons of peripheral information (at times in a not so polite manner) over a period of years, but either overlooked or chose not to share the key bit of information.

Just need the needle, don’t want the haystack…

I am in favor of anything we can do to make cross-disciplinary communications more efficient & effective.

One of my favorite trees is the Larch (here they go by the common name of Tamarack), a conifer that is also deciduous, and one of the dominate trees of the boreal forests, including Siberia (Larix sibirica). Although slightly out of their normal habitat, I have about 2 dozen that nicely shade our house in the summer, turn golden as the late summer dryness comes, and drop their needles – allowing the low winter sun to reach us.http://en.wikipedia.org/wiki/Siberian_Larchhttp://en.wikipedia.org/wiki/Larch

>>Pamela
>>I am thinking it is the weather pattern variation that then sets up the AO.
>>The snow cover is a driver symptom, not a cause, of an impending US cold snap.

I am thinking you are right, Pamela.

Most of the European pressure systems have been 500km south of usual. For the UK this has meant cold high pressures in the winter and stormy winter low pressures all during early summer. This is what is driving the larger snow cover.

But what they want you to believe next is that the increase in Eurasian snow is a result of warming waters in the Arctic brought on by AGW.

The last 3 years we have seen something different in the weather patterns. The big change is the shape of the jet streams that promote cold polar air to flow towards the equator. Some say this is because of a break down in the polar vortex but I am not so sure. Last NH winter we saw a very neg AO with a weak polar vortex which plunged the UK back to LIA conditions, but then the AO in Jan went very positive and what happened? The jet streams still retained their highly contorted shape but the pattern and bad weather moved over to Northern America. The exact same result occurred in the SH, the jet stream undulation is positioned by atmospheric teleconnections (AO/AAO etc) but the undulation itself is driven by another force.

I have been watching the pressure patterns around Australia for the last 40 years, lately there seems to be more low pressure cells interacting with the high pressure cells. With more low pressure cells we get big shifts (bends) in the jet streams. Whatever is driving the higher frequency of low pressure cells is the answer to our changing weather, is it a cooling PDO, a cooling Sun or a combination of both?

Geoff, you seem to be getting a handle on what Milanovic calls spatiotemporal chaos. So what about pole-equator contrasts? Isn’t that what drives asymmetrical semi-annual heat pumps? Thinking in climatological anomalies has blinded the mainstream to the dialing of the nearest harmonics of solar cycle length through the dominant modes of terrestrial oscillations. Combining the insights of Leroux, Sidorenkov, LeMouel, Blanter, Shnirman, Courtillot, & Milanovic is a recipe for much clearer mainstream insight.

If there is increased evaporation prior to large eurasian snowfall, a body of water likely cooled (assuming it wasn’t primarily from soil drying, in which case the surface atmosphere would cool). Formation of snow would release heat in the upper atmosphere, to be radiated away. Third, melt and evaporation of snowpack would cool the surface level atmosphere.

I took snowpack to mean mass, not extent. There is probably much more happening than albedo change. And, as others have suggested, it is likely an effect of some dynamic change and not a cause.

Great post Erl, I especially like this bit. Very interested to read parts 2&3.

Figure 13 shows that the temperature of the sea between the equator and 30°north follows the temperature of the sea at 30-50° north but in a less agitated fashion. It appears that the cloud cover response in tropical waters is less energetic than it is in the mid latitudes. I suggest, no I insist, that the ENSO phenomenon in the Pacific, and climate change on all time scales, is ultimately due to changes in cloud albedo. ENSO is not climate neutral. ENSO is not a driver of climate change. It reflects climate change as it happens just as the ripples on the sea reflect change in the wind. Global temperature trends are not confounded by ENSO dynamics. ENSO is part of the whole, integrating the effects of change that occurs in latitudes where the cloud dynamic is more sensitive than it is in the tropics.

This is kinda old news, the snowfall feedbacks on the the Scandinavian blocking pattern (SCA teleconnection) which is a known precursor modulates the AO/NAO couplet in winter. I believe the folks at AER have used Eurasian Snowpack in the last few of there winter forecasts because of a large correlation coefficient